Traditional multi-power stack solar inverters are used to convert direct current (DC) power into alternating current (AC) power to be supplied for commercial and residential use. The DC power source can be a solar battery (e.g., a plurality of solar cell arrays). The multi-stack includes a plurality of power stacks (e.g., power converters) operating together to produce the AC power to be supplied.
Multi-power stacked solar inverters typically employ passive short-circuit protection devices between an interconnected DC bus. The purpose of such an arrangement is to avoid the consequence of short circuit scenario in a particular power converters DC bus propagating to other power converters. But during an uncertain situation where the interconnected DC power sources (e.g., PV arrays) were not proportional, it naturally results in uncontrolled current circulation between interconnected DC bridges via the passive short-circuit protection devices. This situation can damage the short-circuit protection circuit itself. Hence these inverters limit delivered AC power in proportion to a minimum DC power extracted from different DC power sources (e.g., PV arrays). But de-rating the power converter to avoid this issue will successively degrade the ultimate AC power produced. The possibility of occurrence is so high as environmental conditions (e.g., clouds) can affect one or more of the PV arrays every day.